Vue CLI 全局事件总线 消息的订阅与发布

<template>
<div id="root">
  <div class="todo-container">
    <div class="todo-wrap">
      <MyHeader @addTodo="addTodo"/>
      <MyList :todos="todos"/>
      <MyFooter :todos="todos" @checkAllTodo="checkAllTodo" @clearAllTodo="clearAllTodo"/>
  	</div>
  </div>
</div>
</template>
<script>
  import pubsub from 'pubsub-js'	// 习惯第三方库写上面
  import MyHeader from './components/MyHeader.vue'
  import MyList from './components/MyList.vue'
  import MyFooter from './components/MyFooter.vue'
  export default {
    name:'App',
    components: { MyHeader,MyList,MyFooter },
    data() {
      return {
        todos:JSON.parse(localStorage.getItem('todos')) || []
      }
    },
    methods:{
      //添加一个todo
      addTodo(todoObj){
        this.todos.unshift(todoObj)
      },
      //勾选or取消勾选一个todo
      checkTodo(_,id){
        this.todos.forEach((todo)=>{
          if(todo.id === id) todo.done = !todo.done
        })
      },
      //删除一个todo
      deleteTodo(id){
        this.todos = this.todos.filter(todo => todo.id !== id)
      },
      //全选or取消勾选
      checkAllTodo(done){
        this.todos.forEach(todo => todo.done = done)
      },
      //删除已完成的todo
      clearAllTodo(){
        this.todos = this.todos.filter(todo => !todo.done)
      }
    },
    watch:{
      todos:{
        deep:true,
        handler(value){
          localStorage.setItem('todos',JSON.stringify(value))
        }
      }
    },
    mounted(){
      this.pubId = pubsub.subscribe('checkTodo',this.checkTodo)	// 两种对比
      this.$bus.$on('deleteTodo',this.deleteTodo)
    },
    beforeDestroy(){
      pubsub.unsubscribe(this.pubId)
      this.$bus.$off('deleteTodo')
    }
  }
</script>
<style>
    body {
    background: #fff;
  }
  .btn {
    display: inline-block;
    padding: 4px 12px;
    margin-bottom: 0;
    font-size: 14px;
    line-height: 20px;
    text-align: center;
    vertical-align: middle;
    cursor: pointer;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2), 0 1px 2px rgba(0, 0, 0, 0.05);
    border-radius: 4px;
  }
  .btn-danger {
    color: #fff;
    background-color: #da4f49;
    border: 1px solid #bd362f;
  }
  .btn-danger:hover {
    color: #fff;
    background-color: #bd362f;
  }
  .btn:focus {
    outline: none;
  }
  .todo-container {
    width: 600px;
    margin: 0 auto;
  }
  .todo-container .todo-wrap {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
  }
</style>